Marine wildlife under threat from pollution

Dawn Renton

The potentially devastating effects of marine pollution caused by banned chemicals (PCBs) on populations of orca whales and bottlenose dolphins in European Waters is the subject of new research.

Published in the journal ‘Scientific Reports’, the paper was led by the Zoological Society of London (ZSL) and contributed to by many authors including Scotland’s Rural College (SRUC).

SRUC’s Dr Andrew Brownlow leads the Scottish Marine Animal Stranding Scheme (SMASS), and together with his colleagues Nick Davison and Mariel ten Doeschate, carried out statistical analysis and the development of data visualisation ideas.

The research includes samples taken from over 1,000 stranded or biopsied whales, dolphins or porpoises, taken from many countries involving many different stranding research groups.

Dr Brownlow said: “This work is a significant step forward in our understanding of the effects of pollution in the marine environment. We have known about the harmful effects of persistent organic pollutants, such as polychlorinated biphenyls (PCBs) for decades, but that doesn’t mean their impacts are old news. Man-made chemicals polychlorinated biphenyls (PCBs) have been banned since the 1980s, however they were commonly used in the manufacturing of for example electrical equipment and paints.

“Our recent work shows that their accumulation in the marine environment, most acutely seen in the iconic marine species such as killer whale and bottlenose dolphin, is still a very significant problem today. Because these species are both long-lived and key predators they are at particular risk from pollutants, such as PCB, that increase in concentration as you move up the food chain.

Talking about the research findings, he continued: “The pollution burdens, or levels, we found in some animals in this study were quite alarming and showed they are some of the most contaminated animals on our planet. This burden is likely causing significant harm to their health and reproductive ability, and should be an urgent wake up call that, more than ever before, these populations need our protection.

“The next step is to develop an even stronger understanding the effect of these pollutant burdens, but we also need to develop policy to mitigate any additional stressors which these populations face. It may well be that they will need significant help if their long-term survival is to be guaranteed.”